This is pretty easy! ^^ If you don't want any rain or anything that could be a hindrance to your farming, taking care of the animals, etc., follow these:

After your finished in doing all of your work, don't sleep yet! Save your game first then go to sleep. When the next day comes, watch the television for the weather forecast. If it says it's going to rain, snow, etc. tomorrow, don't save! Load the game or turn it off. You will be back at the time you last saved. Just repeat this procedure every time the weather forecast says it won't be a good weather the next day.

I do this every time because I hate those days!